The Kremlin press service reports that President Vladimir Putin has signed into law a controversial bill that requires nongovernmental organisations (NGOs) which receive funding from abroad to register with the Justice Ministry as "foreign agents."

The law, which was cleared by the upper house of parliament and the Federation Council earlier in July, tightens control on the foreign-funded NGOs by compelling them to file detailed quarterly financial reports on their actitivies to Russian authorities every quarter.

And it makes it possible for targeted NGOs to be subjected to regular and unannounced inspections.

Violations of the law are punishable by sizeable financial penalties or potential imprisonment.

The bill has caused huge concern among activists who fear it will be used to stigmatise NGOs critical of government activities or policies.

Law Criticized

Observers have noted that the term "foreign agent" is synonymous with espionage for many in Russia and other nations.

Yuri Dzhibladze, president of the Democracy Development and Human Rights Center, told RFE/RL's Russian Service that he considered the law "anticonstitutional."

"This is not merely a question of our convictions but also a legal strategy if you wish. I know that a great number of organizations are not going to sign statements that they are acting under somebody's orders," Dzhibladze said.

"The vote on the amendments to the civil and criminal codes has been postponed until the fall. These [amendments] envision sanctions ranging from an official warning to fines and suspension of [NGOs'] activities. We are going to fight these decisions in courts."

Other activists say the law is unclear. The law calls for NGOs that receive foreign funding and engage in "political activity" to register as "foreign agents" but does not spell out what constitutes political activity.

Mikhail Fedotov, chairman of the Presidential Human Rights Council, told RFE/RL's Russian Service that the law comes into force 120 days after its official publication.

"There are four months during which to get ready for the law to come into effect. Perhaps a lot of issues will become clearer by that time. Today, however, I am completely confused when it comes to the definition of 'political activities.' It will be very important to see how its legal implementation unfolds in practice," Fedotov said.

Critics have denounced the measure as part of a crackdown on civil liberties that has accompanied Putin's return for a third presidential term in May.

This month, the U.S. State Department expressed "deep concern" about the NGO law but was rebuked by Russia for "gross interference."

The legislation also has been condemned as unreasonable by the European Union.